1. Field of the Invention
The present invention relates generally to a flexible fastener attached to a mouth edge of a bag, a pouch and the like and functions to open and close the mouth edge.
2. Description of the Prior Art
A typical flexible fastener of the type described is disclosed in Japanese Utility Model Laid-open Publication No. 3-19313. The disclosed flexible fastener comprises a pair of opposed fastener strips having on their respective inner sides a male and a female locking portion for coupling engagement with each other and having their opposed marginal grip portions diverged outward to facilitate grip and manipulation. In order to further facilitate grip, the opposed marginal grip portions are provided at their edges with bulges. For opening the flexible fastener, the opposed marginal grips are gripped and spread apart.
However, the above-mentioned conventional flexible fastener suffers from drawbacks. In the conventional flexible fastener, the bulges are located at the very extremities of the grip portions. On the other hand, far inner parts of the grip portions are gripped by fingers for opening the fastener which are flat and have less friction. Since being made of synthetic resinous film, the flexible fastener is very slippery. This requires tight and forcible grip of the grip portions for opening the fastener which is not a problem where the fastener is opened only a few times. However, there are some circumstances which require one person to open thousands of flexible fasteners repeatedly such as a worker in a grain factory. The worker is likely to have a pain or paralysis of the fingers.